This invention relates generally to improvements in protective head gear or helmets, and more particularly to the type of helmets presently used by motorcyclists. These usually include an outer shell of impact resistant material, a relatively thick liner of cushioning material within the shell, a relatively thin inner cover of soft sheet material, and an interior cushioning pad fastened to the inner cover and closely fitting the head of the wearer, leaving small air spaces between the wearer's head and the inner cover. In warm weather, these helmets become quite uncomfortable due to the fact that only the wearer's face and throat are exposed to the exterior air and then only when certain types of face shields or no face shields at all are used. An important object of this invention is, therefore, the provision of an improved safety helmet having a ventilating system which will supply a gentle flow of air through the interior of the helmet, and means for controlling the flow of air therethrough.